Question about DAL Providers

yevi · July 26th, 2009, 10:03 AM

Won't it be better to use DbProviderFactory instead of using the similar technique presented in the book?
This will save us of creating similar DAL implementations for different Databases like SqlArticlesProvider class, and creating it's instances with Activator.CreateInstance(...).

Are there some limitations?

Lee Dumond · August 1st, 2009, 05:21 PM

The application does essentially use the Factory pattern, but instead of calling it DbProviderFactory, it calls it SiteProvider.

Either way, you still need to provide seperate implementations for each database type (SQL, Oracle, DB2, Vista, or whatever) and create an instance of the required provider as needed.

yevi · August 2nd, 2009, 05:54 AM

Quote:

Originally Posted by Lee Dumond

Either way, you still need to provide seperate implementations for each database type (SQL, Oracle, DB2, Vista, or whatever) and create an instance of the required provider as needed.

Why? can't dbfactory handle all of them?

Lee Dumond · August 2nd, 2009, 09:53 PM

A DbFactory would only be responsible for instantiating the correct provider. You still have to write classes that provide low-level interaction with the various databases.

yevi · August 3rd, 2009, 04:04 AM

I am talking about:

Code:

  using (SqlConnection cn = new SqlConnection(this.ConnectionString))
            {
                SqlCommand cmd = new SqlCommand("tbh_Articles_GetCategoryByID", cn);

Can't I change it to something like:

Code:

DbProviderFactory factory = DbProviderFactories.GetFactory(ProviderName);

            using (DbConnection cn = factory.CreateConnection())
            {
                DbCommand cmd =cn.CreateCommand();

So this will work with all databases?

Lee Dumond · August 4th, 2009, 11:58 AM

What exactly is your GetFactory method "getting"? It's getting a "factory", which is just another fancy name for "provider". And you still need separate factories for each database.

yevi · August 4th, 2009, 04:30 PM

Sorry but i am not getting through ,
asp.net provides 4 factories Odbc, OleDb ,Oracle and Sql.
So with one "generic" implementation I deal with those 4 databases, right?
(instead of SqlArticlesProvider.cs for sql only I can create generic implementation for 4 dbs)

So my initial question was why to reinvent the wheel ?

And thanks for your patience